Preemption:
Whether an Arizona immigration law is preempted by federal law, specifically the Immigration and Nationality Act (INA).

Before Arizona’s immigration law enforcement policy (Support Our Law Enforcement and Safe Neighborhoods Act) went into effect, the United States sued Arizona alleging the law violates the Supremacy Clause arguing the Arizona law is preempted by the “Immigration and Nationality Act” (INA). The United States filed a motion for injunction to prevent enforcement of Arizona’s law until judgment was rendered on the constitutionality. The District Court granted that motion, in part, finding that there were sections of the law that were likely to be preempted by federal law. The Court of Appeals found no abuse of discretion and affirmed the District Court’s holding that the Arizona law is facially preempted.

The court found that Arizona misunderstood the standard for finding a statute facially preempted; Arizona argued that the statute can be applied constitutionally. The actual standard is that the challenger must establish that no set of circumstances exists under which the Act would be valid. The court found the United States met their burden in meeting this standard. One factor in finding in favor of federal preemption is the threat of 50 states layering their own immigration enforcement rules on top of the INA; the concern is that the enforcement of the federal statute is incrementally diminished by each additional state statute.

The court found that Congress intended for the states to be under close supervision of the Attorney General when enforcing immigration laws shown with the language of the INA: “State and local officers shall be directed by the Attorney General”. The use of “shall” forecloses the argument that state or local officers can enforce federal immigration law as directed by a mandatory state law. Therefore, the Arizona law is preempted by federal law.